Both Uses

blithe
in
Babbitt
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Down the echoing spaces of the hall the delegates paraded after Willy Lumsen's banner, the men waving their cigars, the women conscious of their new frocks and strings of beads, all singing to the tune of Auld Lang Syne the official City Song, written by Chum Frink: Good old Zenith, Our kin and kith, Wherever we may be, Hats in the ring, We blithely sing Of thy Prosperity.†
Chpt 13

blithely = in a carefree and happy manner -- often unaware of or ignoring something that should be of concern
He said blithely, as Babbitt helped him with his coat, "We must lunch together some time, and talk over the old days."†
Chpt 15 *

Definitions:

(1) (blithe)
carefree and happy -- often unaware of or ignoring something that should be of concern
(2) (meaning too rare to warrant focus)